Use elvis-operator rather than #try

ee/app/models/design_management/design.rb

@@ -107,9 +107,7 @@ module DesignManagement
     end
 
     def diff_refs
-      strong_memoize(:diff_refs) do
-        head_version.try(:diff_refs)
-      end
+      strong_memoize(:diff_refs) { head_version&.diff_refs }
     end
 
     def clear_version_cache

ee/app/models/design_management/version.rb

@@ -105,7 +105,7 @@ module DesignManagement
     end
 
     def diff_refs
-      strong_memoize(:diff_refs) { commit.try(:diff_refs) }
+      strong_memoize(:diff_refs) { commit&.diff_refs }
     end
 
     def reset